Patent GB-752237-A (GB)
Title: Steam and water separator for sea water evaporators or the like
IPC: B63J1/00
Filed: 1954-02-17
Abstract: An evaporator, especially for the distillation aboard ship of sea water, is provided with a separator 50 for removing entrained water droplets from the steam, the separator having a substantially cylindrical vertical wall 44 and being characterized in that there is disposed therein a volute chamber 36 which has its inlet at the centre of the separator and has its outer wall 56 spaced apart from the wall 44 so as to leave a gap 70; the steam enters the separator through this volute chamber and is discharged with a whirling motion into the cylindrical portion of the separator where the water droplets are centrifugally driven out of the steam, and the dry steam is discharged through a conduit 80 which has its inlet opening 82 facing upstream to the flow of steam circulating around the separator.  Opening 82 is located with respect to the discharge <PICT:0752237/III/1> <PICT:0752237/III/2> end of the volute chamber so that the steam will traverse at least 170 DEG  of arc within the cylindrical portion of the separator.  Wet steam is generated in a boiler (not shown) which forms the lower portion of the apparatus shown in Fig. 1.  The steam is led off through an external conduit, and is then introduced through inlet 12 into primary separating chamber 14 which it enters in a tangential direction.  Most of the salt-containing water is driven from the wet steam by centrifugal force; this water runs down the inner surface of shell 10 and over ring 18, and is returned to the boiler.  The partially dried steam flows through inlet 26 into conduit 20 which is fixed within a central aperture in end-header 16.  The base of conduit 20 is closed by conical plate 22 which, together with ring 18, defines a gap 24 for the flow of water from chamber 14.  Plate 22 prevents water from splashing into chamber 14 from the boiler below.  The steam passes up conduit 20 and enters separator 50; and it then flows in a volute side-opening 58 which form a part of volute chamber 36. This volute chamber is closed at the bottom by plate 60 and at the top by plate 62, and is divided into two passageways 64 and 66 by arcuate wall 68. The steam flows through these passageways and is directed downwards by plate 72 as it enters the outer part of the separator 50; and it then flows in a volute whirl path to wall 44.  The water separates on wall 44 and on perforated plate 38, and then drains through the perforated plate into sump s on header 16, and from thence through pipes 74 and 78 to the boiler. Conduit 80 is spaced from extension 34, the side and top of the separator, and the perforate plate 38 by substantially equal distances.  This arrangement and the gap 70 permits 360 degrees circulation of a portion of the steam within the separator 50; this steam wipes the upstream-extending portion of conduit 80 and prevents water droplets, which may collect thereon, from "creeping" towards the opening 82.  An imperforate plate 86 is secured to perforated plate 38 just below conduit 82, leaving only a narrow peripheral gap for drainage purposes; this plate 86 stops water-entrainment in the steam discharge stream from sump s.  Another embodiment, which is particularly suitable for installation aboard ship, is described wherein the sump s is a circumferential annulus which collects the separated water no matter how tilted the position of the apparatus.